A northern grass skink (file image). Photo: Supplied / Andy McKay
Moving a native population of skinks has contributed to the doubling of the cost of a Porirua sewage tank.
Wellington Water started work on the tank near State Highway 59 in May 2022.
It was designed to capture and hold up to seven million litres of sewage at peak times, such as heavy rain events, then gradually release it back to a treatment plant.
But an assessment of the project in October 2022 found northern grass skinks present at the northern end of the site.
Around 60 skinks were rehomed between September and October last year, which pushed the completion date back by six months from late 2025 to mid-2026.
Porirua City Council documents show that delay contributed to the cost increasing from $85 million in December to $97m which was the new budget requested by Wellington Water.
The tank had an initial budget of $48m in 2021.
Other cost increases included upgrading the existing sewage overflow system at the site, the relocation of the Chorus North Island fibre ducts to the other side of SH59 and $5m for the potential of any other project risks.
Council officers have recommended the budget increase is approved and that the Te Puna Kōrero subcommittee refers the matter to council in their meeting on Thursday.
